The present invention relates to pumps for removing milk from a woman's breast, and particularly to such a pump including a flexible portion for receiving the nipple of the breast in a way which simulates a baby's mouth.
Breast pumps have long been known, but they have, until fairly recently, been used principally in situations where the breast is infected and milk must be withdrawn artificially for a few days, while the infection is present. However, since premature babies have been found to thrive much better when fed human milk than when fed artificial formula milk, many mothers of premature infants have found it desirable to collect their own milk for feeding to their premature babies who are too weak and small to nurse. This may involve a period of several months during which the milk must be artificially withdrawn, because prematurely delivered babies are often hospitalized for three times the length of the time by which they are premature.
The portion of a breast pump which receives the nipple and surrounding portion of the mother's breast in order to suck milk from the breast is called a flange. Previously-known breast pumps have included a flange portion which has been made of a hard material. In some squeeze-bulb hand-operated breast pumps the entire pump, except for the squeeze-bulb, has been made of glass, while disposable hard plastic flanges have been used more recently.
Recently, motorized vacuum pumps have been used to operate as breast pumps. Soxe of these have been similar to the milking machines used for dairy animals, including pulsation control devices which periodically apply and then relieve vacuum in the area inside the flange which is used to receive the nipple and surrounding portion of the woman's breast. In previously-known devices of this type, however, the flange used to receive the nipple and surrounding areola portion of the breast has been of a hard plastics material, and has not very well simulated the natural sucking, squeezing, and massaging of the breast which occurs during natural breast-feeding of an infant. Instead the hard material is likely to slide along the skin of the breast, causing soreness and discomfort.
It is now recognized that the milk produced by a woman's breast is of a different quality when such natural squeezing, sucking, and massaging takes place. The milk produced using the previously known breast pumps of either the hand-operated or mechanically operated types equipped with hard flanges is lower in its content of nutrients than the milk produced when the breast is stimulated naturally by a nursing baby.
Previously-available mechanically-operated breast pumps have included a large vacuum pump which has been portable only with some difficulty. As a result such breast pumps have been rather inconvenient for use by mothers who are not able to remain at home throughout all or most of the day, since a nursing mother ordinarily must relieve the pressure of milk being produced in her breasts every 2-3 hours. Longer time without nursing or pumping the milk from the breasts may soon result in discomfort as the breasts become swollen with the milk contained in them.
Another disadvantage of previously known mechanically-operated breast pumps is that the mechanically-operated pulsation controlling mechanism does not allow a woman to adjust the rate of application and relaxation of suction. Thus the woman is not completely in control of the operation, a factor which leads to an uneasiness which is undesirable for stimulating the let-down and production of milk. Additionally, the vacuum level and capacity of the vacuum pumps of previously-available mechanically-pulsed breast pumps is kept low, in order to prevent tissue damage in case of pulsator malfunction. The withdrawal of milk is therefore slower, using such a breast pump, than when a baby nurses. A nursing baby ordinarily applies a maximum amount of suction very rapidly, and it is this sort of cycle to which the woman physiologically responds best in producing milk. Invariable pulsation rate also prevents a mother using such a breast pump from taking advantage of the larger amounts of milk which can be delivered with each application of suction to the breast at some portions of a period of nursing or breast pumping.
The general result of the various combined disadvantages of previously available mechanical breast pumps is that it takes much longer to pump all of the milk which a breast can produce than it takes for a baby to obtain the same amount of milk by nursing. As a result, a mother is very likely to become tired and stop using the breast pump before delivery of all of the milk produced by the breast at a particular time. This likelihood is further enhanced by irritation of the nipple by the hard, funnel-like flanges previously used. Failure to produce as much milk as desired then often causes psychological problems with milk production, leading to early drying-up of the lactation.
Normally, the period of time during which milk is produced, once let-down has been initiated, is only 7-10 minutes. If all the available milk is not taken within the time of the let-down period, production begins to taper off. Thus, when a breast pump is left in use for too short a period of time for each use, or is incapable of removing all of the milk from the breast, the breast's production begins to decrease, as if a baby were being gradually weaned.
Vacuum pump units for breast pumps, because of their high initial cost and long durability, are usually stocked by such locations as pharmacies, for rental to nursing mothers who need to pump milk from their breasts. However, for the sake of sanitation, the necessary hoses and collection apparatus are normally sold to the mothers. Because there are several different available types of pump mechanisms, it is desirable to have a kit of the necessary additional hoses and collection apparatus which are compatible with all of the readily available pump mechanisms.
What is needed, therefore, is a breast pump which both applies suction and massages at least the areola of a woman's breast during its use, and which, as much as possible, simulates the shape and movement of a baby's mouth and throat, to facilitate pumping the breast milk in a period corresponding more closely to the amount of time which is required for a baby to nurse.
Preferably, such a breast pump should be provided in an easily-portable package, should be controllable in the rate of application of suction and in the number of times suction is applied in a given period of time, and should simulate the feeling, as nearly as possible, of the interior of a baby's mouth and throat on the woman's breast.